I know that searching is my friend. Having been around here for a while, and helped beta-test certain versions of the forum, I sort of know my way around these days.
I searched, and didn't find anything that fixed my problem. There may be other information out there, but if people don't put useful thread subjects, my chances of finding it are slim.
I have tried 32 bit tga files, and transparent PNGs. I have copied existing segments, and edited the fps file to use my textures, as someone so kindly wrote a tutorial on it.
Other than that, I haven't found any other useful information.